Portable Neovim. How to change default data folder? How to avoid registry entries?

Question

I'm trying to make a protable Neovim so I can use my plug&play IDE from a USB thumbdrive on any offline Windows computer.

I managed to store my plugins and my sysinit.vim onto the USB drive and make Neovim use them.

But while testing I realized that Neovim creates some folders on the host computer.

~\AppData\Local\nvim-data\shada and ~\AppData\Local\nvim-data\swap

Are there more?

In the manual I found that I can change where swap files are stored by setting directory which currently is ~\AppData\Local\nvim-data\swap\\

What about the ShaDa directory?

Is there any way to change stdpath('data')?

I guess there is no way to prevent nvim-qt to create registry entries? (beside making my own build)

Answer 1

Are there more?

Swap, undo, shada, log... Whatever is found there.

I can change where swap files are stored

IMO, just set noswapfile and forget it.

What about the shada directory?

Read :h shada-n Get used to this: when you need something it's in the help.

I guess there is no way to prevent

Everything is possible. But, at the very least, shada/viminfo is too useful to switch it off.

Is there any way to change stdpath('data')?

From :h standard-path

The $XDG_CONFIG_HOME and $XDG_DATA_HOME environment variables are used if they exist, otherwise default values (listed below) are used

Answer 2

Background

The Windows environment variable %APPDATA% contains the path to a folder (%USERPROFILE%\Appdata\Roaming) intended for application specific data in a Windows domain environment (Windows computer network) which are machine independent and should roam with users as they log on to different computers.

Local (%LOCALAPPDATA%) and LocalLow folders are for application data that does not roam with the user. Usually this data is either machine specific or too large to roam.

Some programs e.g. the user specific Chrome installer installs to %AppData%, while the system wide installer installs to %ProgramFiles%.

Neovim/Neovim-qt configuration documentation:

• https://neovim.io/doc/user/starting.html#base-directories
• https://github.com/equalsraf/neovim-qt#configuration

How to change Neovim's LOCALAPPDATA to e.g. LOCALMYAPPDATA

Neovim uses as its data and config folder the %LOCALAPPDATA% environment variable. If you want to set a Neovim specific data folder then inside the binary file C:\Program Files\Neovim\bin\ nvim.exe LOCALAPPDATA can be overwritten to e.g. LOCMYAPPDATA with a binary editor (e.g. https://hexed.it/).

LOCMYAPPDATA can be added to the environment variables as a user or system variable (command prompt: rundll32.exe sysdm.cpl,EditEnvironmentVariables) containing the data path you would like Neovim to use.

Be careful not to add or remove bytes as this can disrupt the precise offsets where headers, sections, metadata and instructions are expected to be found.

Answer 3

C:> set LOCALAPPDATA=Z:\appdata
C:> cd Z:\appdata
The system cannot find the path specified.

C:> nvim.exe --headless +":echo 'Vim datapath:'stdpath('data')|q"
Vim datapath: Z:\appdata\nvim-data

C:> cd /d Z:\appdata\nvim-data\shada
Z:\appdata\nvim-data\shada>

#ifdef MSWIN
static const char *const xdg_defaults_env_vars[] = {
  [kXDGConfigHome] = "LOCALAPPDATA",
  **[kXDGDataHome] = "LOCALAPPDATA",**
  [kXDGCacheHome] = "TEMP",
  [kXDGStateHome] = "LOCALAPPDATA",
  [kXDGRuntimeDir] = NULL,  // Decided by vim_mktempdir().
  [kXDGConfigDirs] = NULL,
  [kXDGDataDirs] = NULL,
};
#endif

Source: https://github.com/neovim/neovim/blob/master/src/nvim/os/stdpaths.c#L24

Answer 4

vim.fn.stdpath = function(name)
    return "custom_path/" .. name
end

This will move vim.fn.stdpath to the new directory, but using stdpath() in vimscript still doesn't work.

for _, name in ipairs({ "config", "data", "state", "cache" }) do
    vim.env[("XDG_%s_HOME"):format(name:upper())] = "custom_path/" .. name
end

or modify vim.env, both vim.fn.stdpath and stdpath() can read correctly path